Abstract: A drainage system having a stack, a branch piping and a relief vent for reducing positive pressure in the drainage system. The relief vent is connected to the branch piping between the stack and the trap of the fixture. The relief vent is a unidirectional vent which opens automatically upon the application of positive pressure at the first end of the passageway of the flexible vent member and closes automatically when the pressure is reduced. The drainage system may also include an air admittance valve to relieve negative pressure in the drainage system.

Abstract: A flange assembly (10) for connecting a plumbing fixture to a drain pipe (106) in a fluid sealing relationship. The flange assembly includes a ring (12), an extension (20), a gasket (24) and a connector pipe (30). The extension extends outward from the top surface (12A) of the ring and the connector pipe extends outward from the bottom surface (12B) of the ring. The gasket is mounted over the end of the extension opposite the ring. The top wall (24A) of the gasket has an opening (26) which allows access to the center bore (22) of the extension. The waste outlet (104) of the plumbing fixture is inserted through the opening (26) in the top wall of the gasket into the center bore of the extension. When the waste outlet is inserted into the opening in the gasket, the gasket forms a seal between the waste outlet and the extension.